RFR: 8242564: javadoc crashes:: class cast exception com.sun.tools.javac.code.Symtab$6 [v2]

[Vladimir Petko]

> '--ignore-source-errors' allows generating Javadoc for the packages that contain compilation errors. 
> 
> jdk.javadoc.internal.doclets.toolkit.util.ClassTree generates a type hierarchy for javadoc that may include error types such as 
> 
> class Foo extends Bar {
> }
> ``` 
> where Bar is undefined. 
> 
> The user still wants to generate documentation for Foo and have Bar as a text label. 
> 
> For the unknown class Bar it is impossible to detect the enclosing class/file and javadoc crashes with exception. 
> 
> This PR returns Kind.OTHER for the error types, avoiding the javadoc crash.

Vladimir Petko has updated the pull request incrementally with two additional commits since the last revision:

 - rename test classes as per review comments
 - move test comments into method's javadoc comment

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/17435/files
  - new: https://git.openjdk.org/jdk/pull/17435/files/7b810b23..f30c7b5d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17435&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17435&range=00-01

  Stats: 20 lines in 1 file changed: 9 ins; 6 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/17435.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17435/head:pull/17435

PR: https://git.openjdk.org/jdk/pull/17435